theurge14:Helmet tar is so they can have some extra out there to touch and reapply to the bat as needed. When I was little I thought it was because they dropped their helmets in the dugout in pools of tobacco spit. :P

The Red Sox insist on doing it to poke fun at the Yankees prohibiting their players from doing it(or growing beards, celebrating Christmas, receiving oral gratification, or doing any other fun or human-like activity)